Music has been matched to story since sound and image were combined decades ago. However, there has consistently existed an inherent conflict. The music industry spoke the musical language, and the image industry (including photographers, animators, and cinematographers) spoke the visual language of storytelling.
While there can be overlap, this disjointed understanding of image and sound has often resulted in haphazard pairings of story and soundtrack. Musical soundtracks may be chosen based on popularity or newness, or because they sound “cool” or close enough to a desired experience. The level of effectiveness of such combinations can range from weird to spectacular, depending on the level of experience, exposure, and attention to detail of the visual artist or music supervisor(s) making these choices. Further, artists and professional supervisors with a keen ear and understanding of story and sound often produce compelling pairings. On the other hand, inexperienced or hobby storytellers may have a passion for visuals, but may be handicapped with a limited understanding of the impact of a well-matched soundtrack.
Consider the following: songs typically have a single crescendo, multiple crescendos, or no crescendo at all. Some songs without a crescendo may have a relatively steady volume or intensity that stays generally consistent over the track. Some songs without a crescendo may begin with relatively high volume or intensity that generally decreases over the track. Other songs may begin with relatively low volume or intensity that increases over the track. Still other songs may embody a volume or intensity that varies randomly over the track. These and other musical characteristics of volume and/or intensity over time may be referred to as musical arcs. Likewise, films and video have their major emotional or impactful moments, and filmmakers often want to highlight these moments as significant through a corresponding soundtrack. Such emotional or impactful moments of film and video may be referred to as story arcs.
For higher budget productions, custom composers may be utilized to marry the musical arcs with the story arcs by crafting original scores. These custom songs naturally hit on significant parts of the film, creating an incredibly powerful experience for viewers. However, custom compositions can become prohibitively expensive to commission, particularly for smaller budget and resource-constrained productions and artists. Commissioning a custom composition can also impact the production schedule of a creative project, particularly when using the most skilled composers who are in high demand and have significant lead times.